Let-off mechanism for looms



w. SCOTT.

LET-OFF MECHANISM FOR LOOMS.

APPLICATION FILED AP'II.I1.19I8.

. 1,365,283. Patented Jan. 11;1921.

2 SHEETS-SHEET 2'.

UNITED STATES WILLIAM SCOTT, OF KEIGHLEY, ENGLAND.

LET-OFF MECHANISM FOR LOOMS.

Specification of Letters Patent.

Patented Jan. 11, 1921.

Application filed April 17, 1918. Serial No. 229,029.

To all whom it may concern.'

Be it known that I, VVTLLIAM SCOTT, a subject of the King of Great Britain, and resident of 29 Devonshire street west, Keighley, in the county of York, England, have invented a certain new and useful Improvement in Let-Off Mechanism for Looms, of which the following description, having reference to the accompanying` sheet of drawings, is a specification.

Itrelates to that `class or type of let-olf mechanism for looms in which the weights of the beam and its warp are made use of to exercise a controlling influence for retarding the withdrawal or unwinding of said warp from said beam, andthe object of my present invention is to construct and arrange devices to be used in conjunction with said beam so that the weight of the latter and of the warp wound upon it, is utilized for effecting the retarding of its rotations in such manner that the alteration of the-leverage through which said weight acts is all that is required to meet the varied requirements well known, thus said regulations and adjustments are carried out without the employment of additional weights or springs. Springs when made use of being only to permit a slight yield at the beat up as is 'hereinafter described.

In the accompanying sheets of drawings which are illustrative of my invention- Figure 1 is a sectional end elevation taken on line A B of Fig. 3 and as seen in the direction indicated by the arrow a and illustrates suiiicient of the framework of a loom and parts in connection therewith to show the application of my improved mechanism.

Fig. 2 is a plan of the mechanism illustrated by Fig. l.

Fig. 3 is an elevation of the mechanism as seen from the rear of the loom.

Fig. 4 is a sectional end elevation showing the parts illustrated by Fig. 1 with modifications added thereto as hereinafter described.

Fig. 5 is a view of the parts shown by Fig. 4l as seen in the direction indicated by the arrow b.

Fig. 6 is a similar view to Fig. 4, but shows the parts as seen in the opposite direction to the direction in which the parts shown by Fig. 4 are seen.

C indicates the end frame of the loom, D the back rail on said loom over which the warp passes and E the lower or bottom cross rail of said loom.

In carrying my invention into effect l mount the beam 2 so that it is supported by lever arms 3 which are situated on both ends of the loom although only one of said levers is illustrated by the drawings. These levers 3 are pivoted upon shafts i which are supported by brackets 5 fixed to the end frame C or which may be otherwise mounted, although 1 preferably make use of said arrangement for the reason that by said shafts 4 being mounted :in brackets 5 I can slide them through and secure them within said brackets in order to enable the levers 3 to support a longer or shorter beam 2 within any given loom as will be understood. The mounting of the beam 2 to be supported by the levers 3 is effected by mounting upon said levers 3 sliding brackets `G to which are pivoted blocks `6a by the pin or studv 6". yEachr of these brackets 6 is preferably arranged to be actuated by a screw `7 through the hand wheel 8 in order that said brackets 6 maybe moved'` farther' from ory nearer to the pivotal shaft l as the weight of the beam 2 may have to exercise a greater or less action upon the friction rope or chain 9 to retard its own vrotation as hereinafter described.

The levers 3 in addition to having the horizontal arms carrying the screws 7, have other arms 3l which reach into suitable relative positions with the beam 2 so that the friction chains 9 may be secured to said lever arms 3a. Thus by taking the chains 9 around the beams and securing their other ends to hooks 10, held by brackets 11, the weight of the beam 2 causes said chains 9 to grip their outer ends and thereby retard the rotation of said beams as will be understood. In order that said grippinfr or forcing of the chains 9 by the weight of the beam 2 may be increased or decreased the brackets 6 are arranged to be moved upon the lever arms 3 to carry said beams 2 farther from or nearer to their pivotal supporting shafts 4 thus increasing or decreasing the leverage through which the weight of the beam acts as may be found necessary.

As means for retaining the beam 2 in suitable position relatively with the lever and friction devices described I make use of slotted brackets l2 which are secured `to the cross rail E in order that the axial shaft 13 may take through a slot 12L in said bracket 12 by which it is to be guided, While yet allowing freedom for its movements in a vertical direction so that the actions of the friction devices are not thereby interfered with.

In cases Where it is desired to automatically alter the leverage that the Weight of the warp beam has over the friction device as the Warp upon said. beam is being Withdrawn, therefrom and therefore as it thus varies in diameter, I may have a projection 14 extending from the periphery of the beam 2 to engage or operate a Wheel 15 fixed upon the spindle (or short shaft) 6b which passes through the sliding bracket 6. This shaft 6b has secured to it, at its opposite end, a Worm 17 gearing with a Worm Wheel 18 which will slide upon a feather or key Way on the horizontal shaft 19 as it is carried in said direction by arms 6c extending from the sliding bracket 6. Upon the other end of this shaft 19 is fixed a pinion 20 Which gears with a spur Wheel 21 fixed upon the screw 7. Hence as the beam 2 revolves at each revolution it Will take the Wheel 15 the space of one tooth and said Wheel 15 will rotate the Worm 17 which through the gearing described Will rotate the screw 7 in proportion as arranged for by said gearing.

Although I find that under many circumstances the end of the chain 9 may be held rmly and rigidly and that all the friction or retarding action of the Warp beam 2 may be secured by the Weight of said Warp beam alone yet under certain conditions and to meet the requirements of the resilience of the Warp during the beat-up as hereinbefore explained I make use of yielding springs 22 so that during the exertion of the extra force on the Warp at the time stated (that is during the beat-up) said springs will yield suiciently to meet or to be in conformity With the resilience of the fabric being Woven.

Having now particularly described and ascertained the nature of my said invention What I claim s:-

1. In let-off mechanism for looms, pivoted levers each having a horizontally and vertically extending arm, a screw-actuated bearing slidably mounted on the horizontal arm, a Warp beam mounted upon said screw-actuated bearing, slotted guides for said Warp beam, a flexible brake encircling said beam, one end of said brake being connected to the vertical arm of said lever and the other end connected to an attachment acting under the recoil of a spring, said attachment and said spring.

2. In let-0E mechanism for looms, pivoted levers having extending arms, bearings for supporting said levers, supports mounted upon the horizontal arms of the levers, means for automatically adjusting the distance of the supports from the fulcrums of said levers, a Warp beam mounted to revolve on said adjustable supports, attachments connected to the vertical arms of the levers and means connected to said attachments for retarding the rotary motion of the warp beam.

WILLIAM SCOTT. 

